We are planning another trip to Europe next year and will concentrate
on Germany. I travelled to Germany briefly as a child, once
when I
was about 20 by myself, and twice since on bigger trips of
Europe -
most recently in 2003. Each time as an adult I have relied
on trains
for transport and the German trains are wonderful. I had no
trouble
travelling by myself except sometimes I was a bit lonely as
I had
no-one to share the experience with; no compromises were required
either!

What I have found works well for us is to stop in one city for
a few
days and use the trains to visit other cities from there. We
stay
reasonably close to the station. The advantage is you are not
lugging
your bags around, negotiating a room ... - more time to see
things.

For example we went to Garmisch-Partenkirchen for dinner from
Munich.
We also hired a car for one day to travel to Neuschwanstein
(we were a
family so that was more convenient than a tour for us). The
Romantic
Road can be travelled in a day by bus - the tour I took many
year's
ago had long stops in Dinkelsbuhl, Nordlingen and Rothenburg.
It was
just the bus that leaves outside the Munich railway station
and with a
Eurail or Deutsche Bahn pass costs 1/2 price. You could then
catch a
train back to Munich that evening or of course travel on to
Heidelberg.

Your itinerary then looks a little less hectic as say from
Munich you
see Dachau, Garmisch-Partenkirchen, and Fussen. You are still
covering
a lot of ground so you would still want to work out in advance
when
you will travel and how long you spend on the journey . For
example,
using http://reiseauskunft.bahn.de/bin/query.exe/en
the German rail site you find that from Cologne to Hannover
will take
at least 2 hours 40 minutes and perhaps 3 hours. Add getting
to your
hotel, and that is an afternoon of travelling. You may need
to
compromise depending on how long you wish to spend in each
place.